The long-range goal of this research is to carry out a combined genetic and biochemical analysis of membrane transport in the model organism Neurospora crassa. Work is now in progress in three areas: (1) isolation and characterization of a plasma-membrane ATPase believed to pump H ions out of the cell, thereby creating a large electrochemical gradient for H ion (including a large membrane potential); (2) kinetic and electrophysiological analysis of H ion minus dependent glucose cotransport, and isolation of mutants defective in this process; and (3) a study of transport across the mitochondrial inter membrane, including characterization of the mitochondrial ATPase. BIBLIOGRAPHIC REFERENCES: Slayman, C.W. and C.L. Slayman. Energy coupling in the plasma membrane of Neurospora: ATP-dependent proton transport and proton-dependent sugar cotransport, in Molecular Aspects of Membrane Phenomena (ed. H.R. Kaback, Springer-Verlag), in press. Slayman, C.W. The genetic determination of membrane transport, in Transport Across Biological Membranes, vol. 1 (ed. D.C. Tosteson), in press.